1. Field of the Invention
The present invention relates to a display apparatus which allows hand-written graphic characters of, for example, a letter, a figure, etc. to be entered, more particularly to an apparatus and method for displaying contour lines of a figure, which displays contour lines of a hand-written graphic character created by contouring processing carried out immediately after the hand-written graphic character is entered, as well as a medium on which a program for controlling the apparatus is stored.
2. Description of the Related Art
Related art technologies for drawing contour lines of a graphic character stored beforehand is disclosed in Japanese Unexamined Patent Publications JP-A 58-172768 (1983), JP-A 3-75973 (1991), and JP-A 8-146939 (1996). In JP-A 58-172768 (1983), contour lines of graphic characters stored beforehand are created and displayed by setting a rectangular coordinate system in which each coordinate axis is inclined by 45.degree. to a display rectangular coordinate system set up for the display face beforehand. Consequently, the line width of the contour line in the oblique direction becomes equal to the line widths of the graphic character in both vertical and horizontal directions. The corners of the contour line are thus rounded.
Furthermore, in JP-A 3-75973, both starting and ending points of a stroke are found, then regular polygons inscribing circles drawn around the starting and ending points assumed as center points are found, and after this, a stroke figure inscribing both of the regular polygons, that is, a contour line is found. In addition, in JP-A 8-146939, an original letter stored beforehand is drawn so as to be contoured with a contoured letter. It is possible to specify a width and angle for shifting the contoured letter, as well as a color for the contoured letter.
The related art described above is also used for contouring processing for all of coordinate data representing a graphic character to be contoured. The contouring processing is possible only after all the coordinate data of the graphic character is entered. Consequently, when a curve or the like is drawn freely using a pointing device on digital image data, it is impossible to contour the curve in real time. For example, in the case of a display apparatus which allows hand-written graphic characters of letters, figures, etc. to be entered, it is impossible to display contour lines of the hand-written graphic characters immediately. Additionally the operator cannot confirm the contour lines during contouring processing.